Loss Function not supported error

I am trying to create a custom loss function,

def loss(x,y):
    x_bb=x[:,:4]*224
    x_c=x[:,4:]
    y_bb=y[:,:4]*224
    y_c=y[:,4:]
    return F.l1_loss(x_bb.to(dtype=torch.long),y_bb.to(dtype=torch.long))+F.cross_entropy(x_c,y_c)*20

but it’s throwing me this error

RuntimeError: _thnn_l1_loss_forward not supported on CPUType for Long

I tried with different datatypes and with GPU as well, but got the same error, just instead of “CPUType” it’s showing the same error with “GPUType”

.float() is supported, just do that. It will work.